The present invention refers to a heat storing solar collector device comprising a liquid reservoir with an insulating lid floating on the liquid surface, solar collector means being arranged above the lid for heating of the liquid in the reservoir.
Solar collector devices of the type indicated above are previously known, at which the solar collector means consist of lenses or reflectors which concentrate the incident solar energy onto heat absorption tubes through which a liquid flows. At such known devices circulation systems for transport of the liquid through the absorption tubes are required and moreover, it is normally required that the heat absorption tubes are designed in specific ways in order to take care of the incident solar energy to the maximum extent. Despite advanced designs of the absorption tubes the devices exhibit relatively low efficiency, partly because the lens means and the reflectors respectively cannot even approximately be made optically perfect, which brings about that portions of the concentrated radiation energy beams fall outside the absorption tubes, partly due to the shallow energy absorption depth of the absorption tubes; a relatively large energy absorption depth would be desirable in the light of the wide frequency spectrum of the incident solar energy.
An object of the present invention is therefore to devise a solar collector device of the preamblewise mentioned type, at which said draw-backs are avoided.
Other objects and advantages with the invention will appear in the following.